Motor vehicle brake



May l6, 1933.

P. M. MILLER MOTOR VEHICLE BRAKE Filed Feb. 20, 5 Sheets-Sheet 1 P. M. MILLER MOTOR VEHICLE BRAKE Filed Feb.- 20, 1928 I5 Sheets-Sheet 2 May E6, 1933. P. M. MILLER 1,909,883

MOTOR VEHICLE BRAKE Filed Feb. 20, 1928 5 Sheets-Sheet. f5

Patented May 16, 1933 PHILIP M. MILLER, oF BRooxLxN, NEW YORK Moron VEHIQLE i` Application Bled 'February 20.11328.V -vSe-r'al No. 255,693.` v.

This invention relates .to :motor `vehicles and more particularly to brake mechanism for such vehicles.` i i The invention has for lits .object to ,provide `l means for compensating forthe .wearibetween i the coacting parts ofthe brake mechanism whereby v.the length vof `-service cfu-the brake and the effectiveness of the braking yaction 'are increased.

:Another object of the invention is sto providemeans whereby the coacting parts are accessible and easily removable, forrepairs Vof therworn parts. v

' Anotherobject of the `invention lis topfo- 15 vide `.means whereby .the operating members will produce substantially the same braking action throughout the V.circumzereiice of the fiange of the drum of a motor wheel. f

Another objectof .the inventionvis to `provde a construction in which the braking members are so ymounted thatnthey 'may beas sembled priorV to being secured in place `on motor vehicles.

`.Another.object ofthe invention is to .provide a construction that will be adaptable as a foot and hand brake.`

Other objects and advantages of the i11- vention will be apparent from vthe following Y description of 'the accompanying drawings, in which Fig. l isa-.side elevation oftherdrum of a motor vehicle `and the casingcarrying the braking mechanism, the drum vshowing in section with its mainbody removed to show the interior of the mechanism. 2 is a cross section thereof taken on the line 2 indicated by the arrows; Fig. 3 is a view similar to Fig. l of a moditiedformhe drum being partially in section;` while Fig. 4 isa Vside` elevation of the assembled drum and brake mechanism, showing the rear face of the construction. Y

The brake mechanism is mounted, as is usual, `on the axle or vspindle 5, ofthe front and rear of the motor vehicle, in any well known manner. The brake shoes 6 are pivotally connected as shown at 7 to the casing 18, each of the shoes 'being provided at y'its pivoted end with a terminal or lug `8 through which the pivot pin extends from the :rigid connection with the casing The nut .7a is threadedly securedon the pin 7 and ,is remov` able therefrom in order to permitremovalof the shoes for repairs. Eachend 8 of :the shoesf ,isprovided .with a tapered-faceforming co-operativelyia space 9 therebetweenfin order Ato facilitate movementofthefshoes into Contact with ,the-flange 432 of the drum mem ber 35.. `Each.;of `the slices f6 is @provided with a ,laterally disposed strengthening A.rib

10., which ,may `be centrally'disp'osed if 4de,-`

sired, (and which extends,"` substantially throughout the length ofthe -shoe `and va spring 151 'engages, at its .oppositez'endm pins 12 `carried by the ribs .10, the `spring'to Vretract the `shoes after the Vshoe `actuating means ihasbeenfreleased. y, s The iange 14 -of the casing Ylforms the outer member off' the assembled drum :and brake mechanism, while `the fiange 32 `of :the drum -35 'forms the inner member, and .both casings .13` and l15telescope `one with fanother,

in order to provide a mudproof construction and clearance therebetween. The casing 13 is oppositelyprovided withffxed vpins 11.5 each passing through theslot lfformedl in the ribs i theshoes6, thereby preventingaccidental displacement of the shoes and providing means whereby the shoes slide upon the pins 15-whenthebrake mechanism is in operation, the :pins valso :acting as stopsto limit :the inward movement `of the shoes, in the mannerhereinafter described.

. Thefbrake Shoe actuating mechanism comprises pear-shaped cam :members `17 and 17a,

each provided with corresponding teeth 18,

the teeth of `one engaging 4 the teeth `of lthe other.Y The `opposite end vof eachcam 1member 17 and 17a is of circular f'form' as shown journals 1 in the bushing or opening in the casingl and -islixed to actuating member 2211s `shown in Fig. 4. The lcam members `1.7 and 17a .are, asshown, `in engagement .one

with 'another in order that'the circular ends 1.9` thereof snugly contact with the sides .of

the Yends of fthe ribs 10 :ofthe shoes 6, for

actuating the shoes into engagement with the way as at 23, between the pivoted connectionk 25 upon the casing and the pivotal connection 26 with the member 27. The member 24,'as shown, is also positioned diagonally on the outer surface of the casing at'aisuitable* angle relatively to lmember 27, in. order to provide a pivotal connection 25 in relation with the pivotal connection 23, for thev purpose of aectuating movement of the members whenever the member 27 is moved.

- With the arrangement of the parts as shown, member 17 a is pivoted upon the pin 20 which is fixed in the casing 13, while member 17 is fixed upon the pin 21 which journals in a bushing fixed in the casing and fixed to member 22;. thefopposite end of member 22 is pivoted tomember 24-as at 23; and member 24 which is the longest of the two, is pivoted at one'point 25 to the casing and to member 27 at the other point 26. Members 17 and 17 a permanently engage one another by means ofthe teeth 18,'and the opposite'ends 19 contact with the ends of the ribs 10, which although shown of tapered type, may be-of any type to provideperfect contact withthe members for operating the device.

As shown in Fig. 4, member 24 is further provided with a slot 28 through which the pin 23 passes, and its head holds both memf bers 22 and '24,in' sliding engagement one with another. A spring 29 is secured to the casing as at 15 and to-member 24 asat 30, the' spring acting to retract the members 22, 24 and 27 in cooperation with spring 11 Vwhich act to retract the shoes 6, after the shoe actuating means has been released. Member 40 is' fixed to the casing and acts as al stop to limit inwardmovement of the members.

The members 17, 17 a, 22 and 24 may-'be actuated in any Vsuitable manner and in the form of the invention shown are actuated by means of member 27 which is connectedin the usual manner with an operating lever or foot pedal, or both on the vehicle.

As is well known, the coacting parts of the brake mechanism of a motor vehicle receive hard wear, for instance, the brake lining 31l or other parts, and to compensate for this wear between the coacting parts, the members of themechanism are connected for easy removal and replacement, the nut 7a when In Fig. 3 a modification is shown, wherein the ribs 10 of the shoes 6 are engaged upon the brackets 36 which are fixed to the casing 13, the brackets acting as stops to limit the inward movement of the shoes, as hereinbefore described. Insteadof members 17 and 17er shown in F ig. 1 and hereinbefore described, member 37 is fixed to pin21 and connectively related to members 22, 24 and 27 as in the manner hereinbefore described in connectionwith Fig. 1. Member 37 is provided with a circular major portion 38 and a tongue 39 engaging the ends of' the ribs 10 ofthe shoes 6. l

rlfhe operation of the brake mechanism is herein briefly described as follows: When the motorist rdesires to throw the braking mechanism into operation, the member 27 is moved bymeansof ksuitable foot, hand, hydraulic orother mechanisms attached on the motor verelation vto another and the inner pivotal end 25 acting as a fulcrum for loperating pivotally member 22 in sliding engagement bygits pivot 23 with the sides of the-slot 23 in member 24ffromneutral position, 'to turn member 17 to contact with the rib of the shoe, the i teeth'18 of member 17 engaging in the corre# sponding'teethr 18 of member 17a, and member 17 movesmember into contact with the i rib of the other shoe. U pon further or forcible moving ofthe members 22, 24 and 27 from neutral position, members 17 and 17d are rotated, teeth of one engaging the teeth of the other, with the round ends 19 carried in opposite directions to cause the brake shoes to spread Voutwardly and forcibly and engage the flange 32 of the drum 35, thus wedg-v ing the lining 31'on the shoes thereagainst. y. The manner and the effectiveness of operation of the device shown in Fig. 3, produce the same result of operation and effect as hereinbefore described in relation with F ig. 1.

When the actuating mechanism for the brake has been released the spring 11 retracts the shoes-6 and the spring 29 likewise'retracts the members 22, 24 and 27 to their normal position,in which position the pins 1 5 carried by the vcasing 13 engage the inner side of the slots 16, and the member 24 engages upon the bracket 40, and the ends 9 of the shoes are then retracted to a position that a circumfer` ential space is formed between the shoes and fiange of the drum, in order to prevent frictional contact of one withtheother when the wheel with the drum is revolving under mo.- tion of the motor vehicle. v

From the above description it will be seen that a simple and effective brake mechanism has been devised and moreover, a mechanism by means of which the wear between the con# tacting parts may be compensated for, thereby increasing the life of the brake.

It will also be seen that the mechanism has been so constructed in such a manner that all the operating parts thereof may be assembled before placing the brake in position on the motor vehicle, and the parts are accessible for removal for repairs.

While the embodiments of the invention have been specifically described and illustrated, it should be understood that the invention is capable of modification, variation and substitution Without departing from the spirit and scope of the appended claims.

What I claim and desire to secure by Letters Patent is: l

1. Brake mechanism comprising a drum and a casing having telescoping fianges, pivotally connected brake shoes carried by said casing, a pair of coacting cam members for moving the shoes into contact With the flange of the drum, said cam members being provided With intermeshing teeth, one of said cam members being pivoted to the casing and the other of said cam membersbeing fixed to a shaft Which is extended laterally through the casing, an operating lever fixed to the extended portionof said shaft, and provided with a pivotal member on its free extremity, another operating lever pivotally anchored at one extremit7 to the casing and formed with a slot at an intermediate portion thereof in which the said pivotal member of the first-named operating lever has sliding engagement, a third operating lever pivotally connected to the slotted lever and adapted for operative engagement With brake-operating mechanism, means for retracting the operating lever to a neutral position, means for limiting excess 'movement' of said levers from a neutral position, and means for retracting said brake shoes to a l neutral position.

2. Brake mechanism comprising a brake drum and a backing plate, brake shoes movably connected to said backing-plate and pivotally connected to one another, means for normally urging said shoes to a retracted position, a pair of cam members rotatably i E mounted on the backing plate and adapted to contact With one another and the free ends of the brake shoes, said cam members being provided `with intermeshing teeth, one of said cam members being pivoted to the backing plate and they other of said cam niembers being fixed to a shaft Which is extended transversely through an opening in the backing plate, a lever fixed to said shaft and provided with a pin at its free extremity, an-

other lever pivotally anchored to the backing plate and formed With a slot in Which said pin has sliding engagement, said levers being arranged at an angle with respect to the horizontal, a third lever pivoted to said ated bya brake pedal or analogous member whereby a .compound 'lever'. action is `applied to' said camfmembers for .inoving the brake shoeslfi'nto ,contact With. the yflange. ofthe drum, means:forretractingfthe levers into a neutral position, .and means for preventing excessive retraction movement thereof; 3f Brake mechanism comprising a brake drum` anda backing plate, a plurality ofpivota'lly -connected- .brake .l shoes supported for limited .movement onthe backing plate, y

meansv for normally urging the 'shoesftola retracted position, ya pluralityo-fz cam members `in contact With .one` another and` havingfcamzsurfaces in contact with lthe A free I ends of the shoes, said f camV :members being formed With teeth which intermeshkto-therey by move said `cam membersin Vunison ,when acting tomovethe'shoes into braking engagement with the flange of thedrum, one of said cam members being pivoted to the-,backing plate and another of said cam members being fixed on a shaft Which is journaled in the backing plate and projects transversely i ing engagement With respect to the fiange of Athe drum, comprising a pair of coacting cam members formed With cam portions'which act on the free ends of the brake shoes and toothed portions which intermesh for positive movement of said members in unison .one With another, and means for rotating said cam members to throw the cam portions thereof in counter directions and exert a cam action on the free ends of said shoes.

5. Braking Vmechanism` comprising a flanged brake drum, a backing plate, a plurality of pivotally-connected brake shoes, and means for movingsaidshoes into brakl `ing engagement with respect to the flange of the drum, comprising a pair of coacting pear-shaped combined sector gears and cam members in contact with one another With the gear sectors in constant mesh for positive movement in unison of said members and the cam portions thereof in contact With the free ends of said shoes, and means for rotating said cam members to exert a cam action on the free ends of said shoes.

6. Braking mechanism comprising a flanged brake drum, a backing plate, a plu-- 5 second named lever and adapted to be actu-rality of pivotally-connected brake shoes, a

Vrality of pivotally connected brake shoes, Vand means for moving said shoes into brakpair of coacting cam members formed with Cam portions which act on the free endsfof the brake shoes and toothed portions which inter-mesh for positive movement of said 5 members in'unison one with another, one of said cam members being pivoted to said plate and the other of said members being fixed on a shaft which is journaled in said plate, an operating lever fixed to said shaft and a Vi0 coaeting relatively long operating lever pivotally anchored to said plate and having a sliding pivotal connection with the firstnamed lever, and means formoving said pivotally-anchored lever about its pivot to rol tate said cam members and move the shoes into braking engagement With the flange of the drum.y j Y i' Y Intestimony whereof I alix my signature. 2 vPHILIP M. MILLER. 

